finishing.com -- The Home Page of the Finishing Industry
A website for Serious Education, promoting Aloha,
& the most FUN smiley you can have in metal finishing

HomeFAQsBooksHelpWantedAdvertiseForum
topic 2897

Question About Vertical Anodizing


(1999)

Dear Sirs, We are a Chemical products supplier for finishing industry in MedellÌn, Colombia. One of our customers has started his new vertical Aluminium Anodizing plant since four months ago. They have had several problems, but the most important has been non uniform colour along the profiles. The upper part appear darker than the lower part for all colours they produce (clear bronze to black). The actual composition of the bath is as follows: Sulphuric acid=40 g/l, Tin(II) Sulphate= 15 g/l and Stabiliser Additive=35 ml/l. We would really thank you any recommendation that you can give us to solve this critical problem. Thanking you

Juan JosÈ PavÛn Palacio
- Colombia

Sorry, I'm not familiar with the term "vertical anodizing". Are you describing something different than conventional anodizing, or are you simply noting that the parts hang with the longest dimension up-and-down rather than left-to-right?

I guess that I would have expected the opposite result to what you are getting, i.e., I would have expected the bottom of the parts to be exposed to the dye longest and consequently be darker. Since that is not the case, my guesses would include the possibilities that

Ted Mooney, finishing.com Teds signature
Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey


(2004)

Dear Sir

Ted's response was dealing specifically with the use of organic dyes. Your question is dealing with what is now an old system (But the best, especially if the app' is out-doors - U/Violet light-fast required) O.K with tin sulphate light scattering approaches it is very important to have an anode (TIN) equal to the work area (The aluminium work that has been anodized)- The Cathode and space it equally from the work for uniform deposition. Also of importance is the A.C.,Voltage & Current waveform shapes during this process to be equal on positive and negative cycles. Get the Book from BRACE..."The Technology of Anodizing Aluminum" [link is to info at Amazon about the book]

Robert Fyfe
- Gosford, NSW, Australia



This public forum has 60,000 threads. If you have a question in mind which seems off topic to this thread, you might prefer to Search the Site

ADD a Q or A to THIS thread START a NEW THREADView This Week's HOT TOPICS

Disclaimer: It's not possible to diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & Devices


©1995-2017 finishing.com     -    Privacy Policy
How Google uses data when you visit this site.